Animal Reproduction (AR)
Animal Reproduction (AR)
Original Article

Factors associated with pregnancy rate in fixed-time embryo transfer in cattle under humid-tropical conditions of México

Alfonso Pérez-Mora; José Candelario Segura-Correa; Jorge Alonso Peralta-Torres

Downloads: 0
Views: 59


Abstract: The objective was to determine the effect of some factors on pregnancy rate of fixed-time embryo transfer (FTET), in cows and heifers kept under Mexican tropical conditions. Recipients females (n=405) grazing in pastures were selected according to breed group (Zebu and crosses), parity (nulliparous and multiparous), body condition score (BCS) and the presence of a corpus luteum (CL). The females were synchronized on day 0 using a progesterone vaginal device and 2 mg estradiol benzoate (EB), two groups were established. Group 1 (conventional protocol) were animals in which the progesterone device was removed on day 7. At this time, also received an injection of 50 mg cloprostenol sodium and 1 mg estradiol cypionate. Animals also received 300 IU (heifers) or 360 IU (cows) of eCG. Group 2 (J-Synch protocol) were animals in which the progesterone device was removed on day 6. Cloprotenol and eCG injections were applied as in Group 1. Additionally, on day 9, animals of group 2 received 0.01 mg buserelin acetate. Embryo transfer of in vivo or in vitro was done on day 16 and pregnancy diagnosis was realized by ultrasonography on days 23 and 53 after FTET. Statistical analyses were carried out using Chi-square tests and logistic regression. Pregnancy rate varied between farms (P<0.05). The highest pregnancy rate was for multiparous cows (66%). The recipient utilization rate was better in the J-Synch protocol (85%), and in vivo embryos (75%) had higher pregnancy rate. The diameter of the follicle and the CL had no effect on pregnancy rate (P>0.05). However, the logistic regression determined that the only significant factor on pregnancy rate was the type of embryo. In conclusion, pregnancy rate in FTET females was higher for in vivo embryos than for in vitro embryos in cows evaluated under humid tropical conditions in Mexico.


body condition, embryo in vivo and in vitro, female type, race, recipient synchronization protocol


Alarcón MA, Galina CS, Corro MD, Asprón MA. Embryo transfer, a useful technique to be applied in small community farms? Trop Anim Health Prod. 2010;42(6):1135-41. PMid:20379777.

Ayala A, Delgado R, Honhold N, Magaña J. A visual condition scoring scheme for Bos indicus and crossbred cattle. In: Anderson S, Wadsworth J. Dual purpose cattle production research. Yucatán: International Foundation for Science; 1995. p. 119-28.

Baruselli PS, Ferreira RM, Sá MF Fo, Nasser LF, Rodrigues CA, Bó GA. Bovine embryo transfer recipient synchronization and management in tropical environments. Reprod Fertil Dev. 2010;22(1):67-74. PMid:20003847.

Baruselli PS, Ferreira RM, Sales JNS, Gimenes LU, Sá MF Fo, Martins CM, Rodrigues CA, Bó GA. Timed embryo transfer programs for management of donor and recipient cattle. Theriogenology. 2011;76(9):1583-93. PMid:21798580.

Baruselli PS, Marques MO, Carvalho NAT, Valentim R, Berber RCA, Carvalho FAF, Madureira EH, Costa WP No. Follicular dynamics and pregnancy rate in embryo recipient (Bos taurus indicus x Bos taurus taurus) treated with “Ovsynch” protocol for fixed-time embryo transfer. Braz J Vet Res Anim Sci. 2003;40(Suppl):96-106.

Binelli M, Pugliesi G, Batista EOS, Martins T, Lopes E, Sponchiado M, Diaza AG, Oliveira M, França MR, Cardoso BO, Mello BP, Gomes NS, Latorraca L, Cuadros FC. Programação da receptividade uterina e fertilidade em vacas de corte. Rev Bras Reprod Anim. 2017;41(1):121-9. Available from:

Bó GA, Cedeño A. Expression of estrus as a relevant factor in fixed-time embryo transfer programs using estradiol/progesterone-based protocols in cattle. Anim Reprod. 2018;15(3):224-30.

Bó GA, De la Mata JJ, Baruselli PS, Menchaca A. Alternative programs for synchronizing and resynchronizing ovulation in beef cattle. Theriogenology. 2016;86(1):388-96. PMid:27180326.

Bó GA, Peres LC, Cutaia LE, Pincinato D, Baruselli PS, Mapletoft RJ. Treatments for the synchronisation of bovine recipients for fixed-time embryo transfer and improvement of pregnancy rates. Reprod Fertil Dev. 2012;24(1):272-7. PMid:22394969.

Cerri RLA, Chebel RC, Rivera F, Narciso CD, Oliveira RA, Amstalden M, Baez-Sandoval GM, Oliveira LJ, Thatcher WW, Santos JEP. Concentration of progesterone during the development of the ovulatory follicle: II. Ovarian and uterine responses. J Dairy Sci. 2011;94(7):3352-65. PMid:21700021.

Chebel RC, Demétrio DGB, Metzger J. Factors affecting success of embryo collection and transfer in large dairy herds. Theriogenology. 2008;69(1):98-106. PMid:18023856.

De la Mata JJ, Bó GA. Estrus synchronization and ovulation using protocols with estradiol benzoate and GnRH and reduced periods of insertion of a progesterone releasing device in beef heifers. Taurus. 2012;55:17-23.

De la Mata JJ, Núñez-Olivera R, Cuadro F, Bosolasco D, de Brun V, Meikle A, Bó GA, Menchaca A. Effects of extending the length of pro-oestrus in an oestradiol- and progesterone-based oestrus synchronisation program on ovarian function, uterine environment and pregnancy establishment in beef heifers. Reprod Fertil Dev. 2018;30(11):1541-52. PMid:29778102.

Diskin MG, Waters SM, Parr MH, Kenny DA. Pregnancy losses in cattle: potential for improvement. Reprod Fertil Dev. 2016;28(2):83-93. PMid:27062877.

Ferraz PA, Burnley C, Karanja J, Viera-Neto A, Santos JEP, Chebel RC, Galvão KN. Factors affecting the success of a large embryo transfer program in Holstein cattle in a commercial herd in the southeast region of the United States. Theriogenology. 2016;86(7):1834-41. PMid:27364084.

Gjørret JO, Knijn HM, Dieleman SJ, Avery B, Larsson LI, Maddox-Hyttel P. Chronology of apoptosis in bovine embryos produced in vivo and in vitro. Biol Reprod. 2003;69(4):1193-200. PMid:12773422.

Gonella DA, Grajales H, Hernández A. Ambiente receptivo uterino: control materno, control embrionario, muerte embrionaria. Rev Mvz Cordoba. 2010;15(1):1976-84.

Hansen PJ, Block J. Towards an embryonic world: the current and potential uses of embryo technologies in dairy production. Reprod Fertil Dev. 2004;16(2):1-14. PMid:14972098.

Hasler JF. Factors affecting frozen and fresh embryo transfer pregnancy rates in cattle. Theriogenology. 2001;56(9):1401-15. PMid:11768807.

Instituto Nacional de Estadística y Geografía – INEGI [homepage on the Internet]. Anuario estadístico y geográfico de Tabasco. Mexico: INEGI; 2017 [cited 2020 Mar 23]. Available from:

Looney CR, Nelson JS, Schneider HJ, Forrest DW. Improving fertility in beef cow recipients. Theriogenology. 2006;65(1):201-9. PMid:16289261.

Lozano-Domínguez RR, Asprón-Pelayo MA, Vásquez-Peláez CG, González-Padilla E, Aréchiga-Flores CF. Efecto del estrés calórico sobre la producción embrionaria en vacas superovuladas y la tasa de gestación en receptoras. Rev Mex Cienc Pecu [serial on the Internet]. 2010 [cited 2020 Mar 23];1(3):189-203. Available from:

Macmillan K, Gobikrushanth M, Sanz A, Bignell D, Boender G, Macrae L, Mapletoft RJ, Colazo MG. Comparison of the effects of two shortened timed-AI protocols on pregnancy per AI in beef cattle. Theriogenology. 2020;142:85-91. PMid:31581047.

Mapletoft RJ, Lindsell CE, Pawlyshyn V. Effects of clenbuterol, body condition and non-surgical embryo transfer equipment on pregnancy rates in bovine recipients. Theriogenology. 1986;25(1):172.

Marinho LSR, Sanches BV, Rosa CO, Tannura JH, Rigo AG, Basso AC, Pontes JHF, Seneda MM. Pregnancy rates to fixed embryo transfer of vitrified IVP Bos indicus, Bos taurus or Bos indicus x Bos taurus embryos. Reprod Domest Anim. 2015;50(5):807-11. PMid:26280798.

McEvoy TG, Alink FM, Moreira VC, Watt RG, Powell KA. Embryo technologies and animal health consequences for the animal following ovum pick-up, in vitro embryo production and somatic cell nuclear transfer. Theriogenology. 2006;65(5):926-42. PMid:16280157.

Menchaca A, Núñez-Olivera R, García-Pintos C, Cuadro F, Bosolasco D, Fabini F, Dutra S, De la Mata JJ, Bó G. Efecto de la prolongación del proestro en la fertilidad de los programas de IATF. In: 12° Simposio Internacional de Reproducción Animal; 2017; Córdoba, Argentina. Cordoba: IRAC; 2017. p. 211.

Nasser LFT, Sá MF Fo, Ayres H, Bó GA, Baruselli PF. Factors influencing the in vitro embryo survival after fixed-time embryo transfer. In: International Symposium of Animal Reproduction; 2009; Argentina. Cordoba: IRAC; 2009

Núñez-Olivera R, Cuadro F, Bosolasco D, de Brun V, de la Mata J, Brochado C, Meikle A, Bó GA, Menchaca A. Effect of equine chorionic gonadotropin (eCG) administration and proestrus length on ovarian response, uterine functionality and pregnancy rate in beef heifers inseminated at a fixed-time. Theriogenology. 2020;151:16-27. PMid:32251936.

Pontes JHF, Nonato-Junior I, Sanches BV, Ereno-Junior JC, Uvo S, Barreiros TRR, Oliveira JA, Hasler JF, Seneda MM. Comparison of embryo yield and pregnancy rate between in vivo and in vitro methods in the same Nelore (Bos indicus) donor cows. Theriogenology. 2009;71(4):690-7. PMid:18995895.

Rodrigues M, Bonotto ALM, Acosta DAV, Boligon AA, Corrêa MN, Brauner CC. Effect of oestrous synchrony between embryo donors and recipients, embryo quality and state on the pregnancy rate in beef cattle. Reprod Domest Anim. 2018;53(1):152-6. PMid:28960511.

Roper DA, Schrick FN, Edwards JL, Hopkins FM, Prado TM, Wilkerson JB, Saxton AM, Young CD, Smith WB. Factors in cattle affecting embryo transfer pregnancies in recipient animals. Anim Reprod Sci. 2018;199:79-83. PMid:30442469.

SAS Institute Inc. SAS/STAT® user’s guide, version 9. 4th ed. Cary: SAS Institute Inc.; 2015.

Stringfellow D, Seidel S. Manual de la sociedad internacional de transferencia de embriones. 2nd ed. Illinois: Sociedad Internacional de Transferencia de Embriones; 1990. p. 79.

Stroud B, Hasler JF. Dissecting why superovulation and embryo transfer usually work on some farms but no on others. Theriogenology. 2006;65(1):65-76. PMid:16289325.

Wu B, Zan L. Enhance beef cattle improvement by embryo biotechnologies. Reprod Domest Anim. 2012;47(5):865-71. PMid:22128751.

Submitted date:

Accepted date:

5eff24e40e8825dd0bf8e226 animreprod Articles
Links & Downloads

Anim Reprod

Share this page
Page Sections